Today's hair conditioners almost universally comprise high levels of high melting point fatty compounds, the most common of which are C16 to C18 fatty alcohols. These high melting point fatty compounds are employed as structuring agents wherein they are combined with one or more surfactants and an aqueous carrier to form a gel network. The gel network increases the viscosity and yield point of the product which facilitates the dispensing of the conditioner from a bottle or tube and the subsequent distribution and spreading of the product through the hair by the consumer. The structuring of the product via gel network also enables incorporation of silicones, perfumes and oils in the form of an oil-in-water emulsion that is phase stable. The silicones and oils are intended to be deposited on the hair to provide the primary hair conditioning benefits including wet and dry combing friction reduction and improved hair manageability.
However, today's gel network hair conditioners may lead to co-deposits of the high melting point fatty compound on the hair over multiple cycles. These co-deposits can lead to waxy build-up on hair and weight the hair down. Indeed, one of the major consumer complaints with hair conditioners is often waxy residue which can make hair look greasy or feel heavy. Many current gel network hair conditioners deposit up to 10 times more high melting point fatty compounds (fatty alcohols) than silicones or oils after approximately 10 treatment cycles in technical testing. While not being bound to theory, this is hypothesized to be due to the approximately 10× greater concentration of high melting point fatty compounds in the product relative to the silicone or oil. However, such a high level of melting point fatty compounds (fatty alcohols) has been required to produce a shelf stable gel network with sufficient structuring for consumer acceptable viscosity and rheology.
There is also a desire by many consumers for conditioners that are free from ingredients that are perceived as being non-natural or “synthetic”. These non-silicone conditioners may incorporate oils that are derived from natural sources including vegetable based oils and oil derivatives.
Described herein is a non-silicone concentrated hair care conditioner composition that enables new product opportunities and consumer benefits by addressing the previously described disadvantages associated with conventional gel network conditioners and which incorporates oils in the form of a nano-emulsion. Is has been found that concentrated, ultra-low viscosity hair conditioner compositions can be delivered to the hair in foamed form. These new concentrated oil nanoemulsion compositions enable sufficient dosage from a foam delivery form while also substantially eliminating the need for high melting point fatty compounds or other “insoluble” structurants (from “wax” structured to “gas” structured) that can lead to significant co-deposits, build-up and weigh down of hair. The net result has been a step change improvement in oil deposition purity versus today's rinse-off conditioners and an improvement in technical performance benefits from such a pure and transparent deposited oil layer. These benefits can include multicycle hair conditioning without hair weigh down, durable conditioning, reduced hair dye fade, and increased color vibrancy.
Nanoemulsion technology development is hindered by complex stability issues that emerge when droplet sizes are driven to the nanoscale. This is especially problematic in the presence of higher levels of perfume oils required for such a concentrated product. The concentrated hair care composition described herein is therefor also focused on improved stability.